New Study Validates Bright Light Therapy

One of the lead researchers on a Harvard Medical School study told delegates at the American Academy of Neurology (AAN) 66th Annual Meeting that “Light therapy may be a novel nonpharmacological intervention for Parkinson disease.”

Sleep disturbances, he said, are among the most common and disabling nonmotor manifestations of PD, affecting as many as 90% of patients. “Exposure to bright-light therapy was associated with significant improvement in excessive daytime sleepiness, and this effect persisted to the end of the intervention and 2 weeks after,” said Dr. Videnovic. “No similar effect was observed in the group treated with dim red-light therapy.”

Medscape reporter Pauline Anderson writes that a chronic experimental model of PD reveals that exposure to light facilitated recovery of motor function. “The current study included 30 patients with PD (13 men and 17 women; mean age, 63 years) who were experiencing EDS, defined as an Epworth Sleepiness Scale (ESS) score of 10 or more,” writes Anderson. “Researchers randomly assigned these patients to a bright-light (5000 lux) group or to a dim red-light (less than 300 lux) control group. Participants received the light therapy in 1-hour sessions twice a day for 2 weeks (lux is the measure of light intensity at a specific distance from a light source).”

Session chair, Bradley V. Vaughn, MD, professor, neurology, University of North Carolina School of Medicine, Chapel Hill, commented in Medscape that it’s still early days for interventions such as bright-light therapy in PD. “We are still early in the process of trying to figure this out,” he said. “However, from the results Dr. Videnovic presented here, clearly this is something that is encouraging and exciting.”